Bhagavad Gita · 3.20

कर्मणैव हि संसिद्धिमास्थिता जनकादयः।लोकसंग्रहमेवापि सम्पश्यन्कर्तुमर्हसि॥

karmaṇaiva hi saṁsiddhim āsthitā janakādayaḥ loka-saṅgraham evāpi sampaśhyan kartum arhasi

By action alone, King Janaka and others attained perfection. You should also perform action, considering the welfare of the world.

— Bhagavad Gita 3.20

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)